Spot-crowned barbets in Panama


This video says about itself:

Spot-crowned Barbet Male And Female Feeding Together – Jan. 14, 2019

Here is a good look at the variation between male and female Spot-crowned Barbets! These birds can be found in Panama and Columbia in low to mid-elevation forests feeding on fruits and insects.

Watch LIVE 24/7 with highlights and viewing resources at http://allaboutbirds.org/panamafeeders

The Panama Fruit Feeder Cam is a collaboration between the Cornell Lab of Ornithology, the Canopy Family, and explore.org.

Aso, a clay-coloured thrush present on this video.

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Painter Frans Hals exhibition in the USA


Frans Hals (Dutch, 1582/83–1666), Children of the Van Campen Family with a Goat-Cart (fragment), ca. 1623–25, oil on canvas. 152 x 107.5 cm. Royal Museums of Fine Arts of Belgium, Brussels, inv. 4732. ©Roya

This painting is by Frans Hals (Dutch, 1582/83–1666); Children of the Van Campen Family with a Goat-Cart (fragment), ca. 1623–25, oil on canvas. 152 x 107.5 cm. Royal Museums of Fine Arts of Belgium, Brussels, inv. 4732.

By David Walsh in the USA:

An exhibition of the great 17th century Dutch painter

Frans Hals Portraits: A Family Reunion at the Toledo Museum of Art

17 January 2019

The Toledo [Ohio] Museum of Art recently presented an exhibition featuring works by one of the leading Dutch painters of the 17th century—Frans Hals Portraits: A Family Reunion.

The Dutch “Golden Age” produced a host of extraordinary artistic figures, including most prominently Rembrandt van Rijn (1606–69), Hals (c. 1582–1666) and Johannes Vermeer (1632–1675). Other brilliant painters, of everyday life, domestic and tavern scenes, of landscapes and seascapes, of still lifes and historical events, included Jan van Goyen (1596–1656), Salomon van Ruysdael (c. 1602–1670), Judith Leyster (c. 1609–1660), Adriaen van Ostade (1610–1685), Gerrit Dou (1613–1675), Gerard ter Borch (1617–1681), Jan Steen (c. 1626–1679), Jacob van Ruisdael (c. 1629–1682), Pieter de Hooch (1629–1684) and Nicolaes Maes (1634–1693).

The Hals exhibition will next run at the Royal Museums of Fine Arts of Belgium in Brussels from February 1 to May 19 and later at the Fondation Custodia, an art museum in Paris focusing on works by European old masters.

The exhibition was prompted by the Toledo museum’s acquisition in 2011 of Hals’s The Van Campen Family Portrait in a Landscape (c. 1623–25), along with the recent conservation work done on the Brussels museum’s Three Children of the Van Campen Family.

Remarkably, as the Toledo museum website explains, “These two works [by Hals] originally formed one composition, separated for unknown reasons likely in the late 18th century or early 19th century. The exhibition reunites the sections of the Toledo/Brussels painting along with a third fragment from a private collection.” In other words, this was the first time in some 200 years that three pieces of the original painting were present in the same location.

The curators also offered a proposed reconstruction of Hals’s complete painting as it might have looked when it was painted nearly four centuries ago.

Frans Hals (Dutch, 1582/83–1666), Family Group in a Landscape, ca. 1645–48, oil on canvas. 202 x 285 cm. Museo Thyssen-Bornemisza, Madrid, inv. 1934.8. ©Museo Thyssen- Bornemisza, Madrid

Additional works by Hals were featured in Toledo, including Family Group in a Landscape (c. 1645–48) from the Museo Thyssen-Bornemisza, Madrid; Family Group in a Landscape (c. 1647–50 ) from the National Gallery in London; Marriage Portrait of Isaac Massa and Beatrix van der Laen (c. 1622) from the Rijksmuseum, Amsterdam; and Portrait of a Dutch Family (mid-1630s) from the Cincinnati Art Museum. Also on display were Portrait of a Seated Man Holding a Hat and Portrait of a Seated Woman Holding a Fan (both c. 1650, from the Taft Museum of Art, Cincinnati, Ohio).

A good portion of the catalogue published to accompany the exhibition is devoted to explaining the facts of the Van Campen family painting and proving that the three pieces belong together (along with other still unknown ones). The case seems convincing, but that is a matter for art historians and experts to debate and determine.

The Toledo exhibition was not large, nine paintings by Hals (including the three separate fragments), but the work was all beautiful.

Frans Hals was born in 1582 or 1583 to Adriana and Franchoys Hals in Antwerp, then in the Spanish Netherlands. Starting in the 1560s, the “Seventeen Provinces,” including present-day Netherlands and Belgium, had risen in revolt against the rule of Philip II of Spain, the Habsburg monarch. The struggle lasted for some 80 years. The Dutch uprising was bound up with the transition from feudalism to capitalism.

Antwerp became the capital of the Dutch revolt. However, the Spanish forces counter-attacked and their troops, under the Duke of Parma, laid siege to Antwerp in July 1584. The city surrendered in August 1585 to the Spanish, who gave the Protestant population four years to settle their affairs before leaving.

Hals’s parents apparently fled during the siege, some 110 miles, to Haarlem in the new Dutch Republic to the north, where the artist lived for the rest of his life. Hals apprenticed as a painter starting in 1603. In 1610, he registered with the St. Lucas Guild, which, as the museum catalogue explains, “enabled him to establish his own workshop.”

Hals married twice. He had three children with his first wife, Anneke Harmendr, only one of whom survived early childhood. Anneke died in 1615, and two years later Hals married Lysbeth Reyniersdr, who bore 11 children (four of whom became painters).

The painter’s naturalistic work fell largely from favor in the 18th century, as a tendency even in Holland toward more aristocratic and classicistic academicism took shape, and was only “rediscovered” in the second half of the 19th.

Hals is now widely admired. Critics, historians and museumgoers alike are impressed, in the words of one commentator, by his “vigorous, slashing style.” The painter is always “amazing in fidelity, astounding in surety and vitality of draughtsmanship. Among the Dutch [Hals is] inferior in genius only to Rembrandt, [and] his influence was almost as far-reaching.” (Blake-More Godwin, Catalogue of European Paintings, The Toledo Museum of Art)

Another study argues that in Hals’s portraits, “the quick and decisive look of each stroke suggests spontaneity, the recording of one specific instant in the life of the sitter.” The complete picture “has the immediacy of a sketch. The impression of a race against time is, of course, deceptive. Hals spent hours, not minutes,” on his canvases, “but he maintains the illusion of having done it in the wink of an eye.” (A Basic History of Art, H. W. and Anthony F. Janson)

Frans Hals, Portrait of a Seated Woman Holding a Fan, c. 1650, Taft Museum of Art, Cincinnati, Ohio

Hals came to specialize in portraiture. The Toledo exhibition had several magnificent examples. Seated Man Holding a Hat and Seated Woman Holding a Fan (the subjects’ names are unknown) are assumed to be a newly married couple. Hals scholar Seymour Slive describes the pictures as among “Hals’s most sympathetic portraits of a husband and wife.” She in particular makes an impression, gazing at the viewer confidently.

The painter made a name for himself with his group portraits. Writing of the famed Banquet of the Officers of the St. George Civic Guard (1616, not in the exhibition), Lawrence W. Nichols, the Toledo museum’s senior curator of European and American painting and sculpture before 1900, notes that, in contrast “to the stiff formality typical of the genre, Hals’s poses, gestures, and animated countenances—many conveying engagement with one another, and others rendered as peering out at the beholder—all induce the sense of being a firsthand witness to the actual gathering.” A contemporary of Hals’s, the historian of Haarlem, wrote in 1648 that his “paintings are imbued with such force and vitality that… they seem to breathe and live.”

Frans Hals (Dutch, 1582/83–1666), The Van Campen Family in a Landscape (fragment), ca. 1623–25, oil on canvas. 151 x 163.6 cm. Toledo Museum of Art, Toledo, Ohio, inv. 2011.80

In Hals’s first family group portrait, the work at the center of the Toledo-Brussels-Paris exhibitions, The Van Campen Family in a Landscape, the painter continued—Nichols asserts—“to visually communicate a sense of immediacy … Moreover, he confronted the pressing challenge incumbent on a painter of group portraits of any category: how to capture individuality as well as the collective dynamic of the group and each individual’s relationship to it.” Van Campen, a cloth merchant, his wife and seven children are represented in one of three fragments; a second, narrower picture shows four children; and a third includes the head and torso of a boy (apparently another Van Campen son).

Nichols writes: “Hals’s arrangement is nothing less than the visualization of a household jubilantly being together—their familial cohesion is rendered palpable and is the painting’s very subject. … Gijsbert Claesz [van Campen] gazes out at the viewer as if to proudly present his progeny. Only the two babies … also engage us directly; all the others are involved in or reacting to the spectacle the painter has contrived. … Hals’s vivacious and animated portrait, with its expressive poses, gesticulating hands, and exuberant countenances, was ground-breaking.”

One of the prominent features of the Family Group from the Museo Thyssen-Bornemisza in Madrid is the presence of a black child. The catalogue notes that black youths made their appearance as servants in Flemish and Dutch portraits from the 1630s, “not coincidentally after the Dutch West India Company was established in 1621 and took control of Dutch involvement in the Atlantic trade of enslaved Africans.” The individual “in the present work is as much a specific personality as the rest of the family. That Hals represented him with such dignity and humanity, in conjunction with his relatively substantial wardrobe … suggests that he may have been of high birth, perhaps someone from West Africa who came to Holland for his education or part of a trade delegation.”

Frans Hals (Dutch, 1582/83–1666), Marriage Portrait of Isaac Massa and Beatrix van der Laen, ca. 1622, oil on canvas. 140 x 166.5 cm. Rijksmuseum, Amsterdam, inv. SK-A-133. ©Rijksmuseum, Amsterdam

A painting that deserves its own essay is Marriage Portrait of Isaac Massa and Beatrix van der Laen, described as “an unmitigated standout in the collection of the Rijksmuseum in Amsterdam.” Mariët Westermann (A Worldly Art—The Dutch Republic 1585–1718) argues that there “are no direct Dutch precedents” for this double portrait.

Massa and Beatrix lean back against a tree or an embankment. He smiles at the viewer. “Beside him to the right,” as a 1910 catalogue of Hals’s works described it, “sits a woman, bending slightly forward, with her head turned three-quarters left. She smiles rather slyly at the spectator.”

Again, Hals is a pioneer in presenting human relationships in a flexible and informal manner. The famed Rijksmuseum observes that the “happy, smiling pair sits comfortably close to each other. Posing a couple together in this way was highly unusual at the time.”

We know something about Massa, born into a wealthy silk merchant’s family and sent to Moscow at 15 to assist the family trade, including the fact that Hals painted him several times. Massa also served as a witness at the baptism of one of Hals’s daughters. They presumably were friends.

Frans Hals, Isaac Abrahamsz. Massa, 1626, Art Gallery of Ontario

Massa, an intriguing figure, belongs to the epoch when the bourgeoisie, in its ascendancy, played a revolutionary role. The Toledo museum catalogue describes him as a “polymath of sorts.” According to historian G. W. van der Meiden, Massa “played a prominent part in the beginnings of diplomatic contact between Russia and the Netherlands. He was a many-sided intellect … Thanks to his eye-witness report on the Time of Troubles he is well-known in Russian historiography.” (“Isaac Massa and the Beginnings of Dutch-Russian Relations”)

Massa authored a famed “Short Narrative” on the events of the “Time of Troubles” (1598–1613), a period of civil war in Russia, which ended with the establishment of the Romanov Dynasty. He also was an eye-witness to the terrible famine of 1601–03, which is estimated to have killed one third of the Russian population. Massa extensively describes the suffering. At one point in his “Narrative”, he writes that “Heaven inflicted on the whole country of Muscovy scarcity and famine of which history records no similar examples.”

Massa also published five maps of Russia, including an effort to render the Siberian coast. Van der Meiden writes that Massa “learnt Russian” and that, although “he had received very little formal education, his curiosity was insatiable.”

The same, of course, could be said about Hals himself.

In 1626, Hals painted a portrait of Massa leaning over the back of a chair toward the viewer in an astonishingly informal and intimate pose. The critic John Berger (“Hals and Bankruptcy” in About Looking ) asserted that Massa’s “expression is another one that Hals was the first to record. It is the look of a man who does not believe in the life he witnesses, yet can see no alternative. He has considered, quite impersonally, the possibility that life may be absurd. He is by no means desperate. He is interested. But his intelligence isolates him from the current purpose of men and the supposed purpose of God.” This appears generally legitimate considering what we know of Massa’s life and some of the terrible things he had seen. Berger, in the same essay, also claimed that no one “before Hals painted portraits of greater dignity and greater sympathy.”

Writing of the larger trend, art historian Arnold Hauser (in The Social History of Art, Volume II) observed that “Dutch art owes its middle-class character, above all, to the fact that it ceases to be tied to the Church. … Representations of real everyday life are the most popular of all: the picture of manners, the portrait, the landscape, the still life, interiors and architectural views.” Such motifs “acquire an autonomous value of their own; the artist no longer needs an excuse to portray them. … It is as if this reality were being discovered, taken possession of and settled down in for the first time.”

The bourgeois conditions of life did not make things easy for the Dutch painters, who were “free” of noble and Church patronage and thrown on the marketplace. The resulting state of artistic production, wrote Hauser, allowed “the boom on the art market to degenerate into a state of fierce competition, to which the most individual and most original talents fall victim. There were artists living in cramped circumstances in earlier times, but there were none in actual want.” The Dutch artists’ financial troubles “are a concomitant of that economic freedom and anarchy in the realm of art, which now comes on the scene for the first time and still controls the art market today. Here are the beginnings, too, of the social uprooting of the artist and the uncertainty of his existence.”

Hals went bankrupt in 1652. Rembrandt was effectively declared bankrupt in 1656. Vermeer left his wife in debt at the time of his early death in 1675. She wrote in a petition that during the “ruinous” Franco-Dutch War (1672–78), her husband “not only was unable to sell any of his art but also, to his great detriment, was left sitting with the paintings of other masters that he was dealing in.”

Every opportunity should be taken to see the work of Hals and the other Dutch painters.

The author also recommends:

Seventeenth-century Dutch paintings at the Museum of Fine Arts in Boston
[29 October 2015]

Prehistoric hyenas, video


This 17 January 2019 video says about itself:

Chasmaporthetes, also known as hunting or running hyena, is an extinct genus of hyenas distributed in Eurasia, North America, and Africa. It lived during the Pliocene-Pleistocene epochs, from 4.9 million to 780,000 years ago, existing for about 4.12 million years.

The genus probably arose from Eurasian Miocene hyenas such as Thalassictis or Lycyaena, with C. borissiaki being the oldest known representative. It was a fast runner and an important carnivore on 4 continents during the Pliocene.

At least nine species are currently recognised. The genus type species is Chasmaporthetes ossifragus. It was assigned to Hyaenidae by Hay (1921), Geraads (1997), and Flynn (1998).

The species C. ossifragus was the only hyena to cross the Bering land bridge into the Americas. C. ossifragus ranged over what is now Arizona and Mexico during Blancan and early Irvingtonian Land Mammal ages, between 5.0 and 1.5 million years ago.

Chasmaporthetes was one of the so-called “dog-like” hyenas (of which the aardwolf is the only survivor), a hyaenid group which, in contrast to the now more common “bone-crushing” hyenas, evolved into slender-limbed, cursorial hunters like modern canids.

The genus has entered the popular culture lexicon as a result of cryptozoologic claims, having been proposed as the likely origin of the American Shunka Warakin and the Cuitlamiztli.

Chasmaporthetes was named by Hay (1921), who noted the name to be a reference to the possibility that the beginning of the Grand Canyon was witnessed by the North American species, C. ossifragus.

The limb bones of Chasmaporthetes were long and slender like those of cheetahs, and its cheek teeth were slender and sharp-edged like those of a cat. Chasmaporthetes likely inhabited open ground and was a daytime hunter.

In Europe, the species C. lunensis competed with the giant cheetah Acinonyx pardinensis, and may have preyed on the small bourbon gazelle (Gazella borbonica) and the chamois antelope (Procamptoceras brivatense).

The North American C. ossifragus was similar in build to C. lunensis, but had slightly more robust jaws and teeth. It may have preyed on the giant marmot Paenemarmota, and competed with the far more numerous Borophagus diversidens.

A study on the genus’ premolar intercuspid notches indicated Chasmaporthetes was likely hypercarnivorous rather than durophagous as its modern cousins (excluding the aardwolf) are.

Like most of the animals of the time, reasons for its extinction are not known.

British Thatcherite police on trial for Hillsborough football disaster


This video from England says about itself:

Liverpool fans sing anti Thatcher song at Sunderland. Sept. 15th 2012.

Liverpool fans make their feelings known in the wake of the Hillsborough “real truth” report.

By Thomas Scripps in Britain:

UK: Trial begins of police commander in 1989 Hillsborough football disaster

17 January 2019

The prosecution began its case against David Duckenfield and Graham Mackrell on Tuesday, for charges relating to the deaths of 96 Liverpool fans following the disaster at Hillsborough football stadium in Sheffield, on April 15, 1989.

Duckenfield was the South Yorkshire Police match commander in charge of policing the stadium on that day and faces 95 counts of gross negligence manslaughter. Mackrell was Sheffield Wednesday Football Club’s designated safety officer at the time and is charged with contravening the stadium’s safety certificate and a health and safety offence.

Retired police officers Donald Denton and Alan Foster, and police solicitor Peter Metcalf, are due to stand trial later in the year for acts tending and intending to pervert the course of justice.

The Hillsborough families have worked for decades to achieve justice for their loved ones. The trial of Duckenfield and Mackrell, who will now be properly cross-examined, is a welcome landmark in their campaign.

Addressing Preston Crown Court, Richard Matthews QC outlined the prosecution’s case against Duckenfield. In addition to failures to plan for the crowds beforehand, he said, “Sadly, there were also many collective and individual failures to intervene effectively once the disaster unfolded.” Duckenfield failed to declare a major incident or use emergency measures to help those in danger. “Nor did he make any attempt to even monitor what was occurring, let alone avert the tragedy.” He also failed to provide “emergency medical attention, particularly attempts at resuscitation” in a timely fashion.

Duckenfield, the court was told, had “ultimate responsibility” for the police operation. “It is the prosecution’s case that David Duckenfield’s failures to discharge this personal responsibility were extraordinarily bad and contributed substantially to the deaths of each of those 96 people who so tragically and unnecessarily lost their lives.”

Mackrell, Matthews said, “[E]ffectively shrugged off all responsibility” for arrangements for admission to the ground and the drawing-up of contingency plans—“important aspects of the role he had taken on as safety officer.” By “agreeing to, or at the very least turning a blind eye to” the fact the fact that the club had failed to agree methods of entry to the stadium with police, he is alleged to have breached the conditions of the club’s safety certificate.

More than 20 family members of those killed at Hillsborough sat in the public gallery and other relatives watched from Liverpool via a video link.

What the events at Preston Crown Court highlight above all is the immense scale of the state cover-up carried out over the Hillsborough events—presided over by successive Conservative and Labour governments alike. It has taken fully 30 years of tireless campaigning, at great personal cost to those involved, in the face of vicious media lies and government opposition, for the bereaved families to see anyone finally held to account for the worst sporting disaster in British history.

The government and the press initially responded to the deaths caused by actions of various institutions of the state by blaming a “tanked-up mob” of Liverpool fans and lauding the actions of “brave cops.” The first official report, carried out by Lord Justice Taylor in 1989, was forced to admit some of the truth, pointing to police mismanagement of the event and criticising South Yorkshire police for blaming Liverpool supporters instead of accepting responsibility themselves. However, no one was charged or even disciplined as a result of these findings. An inquest ruled that the 96 deaths were “accidental.”

In 1997, due to mounting pressure, the incoming Labour government ordered the scrutiny of new evidence, which had been brought to light by campaigners and documentary makers in the previous eight years. It emerged that South Yorkshire police changed 164 officers’ accounts of the disaster before sending them to the Taylor inquiry. Prime Minister Tony Blair refused to call a new public inquiry, however, writing “What is the point?” Blair’s Home Secretary Jack Straw claimed that nothing significant had been added by the new evidence.

It took more than a decade’s campaigning and protests by the families and their supporters for the Labour government to finally establish the Hillsborough Independent Panel (HIP), in 2009. The HIP published a report in 2012 which demolished the official police narrative and established that it was not the fans who were responsible for the deaths but the police and the authorities. Then Home Secretary Theresa May was forced to order a criminal inquiry. Now, six years later, and nearly 30 years after the event itself, the first trials of those involved have begun.

This is despite all the evidence and materials for a prosecution of the real criminals being available within the first days and weeks after the disaster. The tortured process leading to the first trials is entirely the result of the state’s efforts to deceive and delay the Hillsborough campaigners’ pursuit of the truth and justice—a deliberate strategy to render a proper accounting for the disaster impossible.

So long has the fight for justice taken that many individuals involved in the events that led to the deaths and their cover-up—including the filthy slander campaign against Liverpool fans which followed it—have died without ever facing investigation or being asked to testify.

Chief amongst these is former Tory Prime Minister Margaret Thatcher. Her government defended the officials at Hillsborough to the hilt and supported the right-wing media and Tory MPs in smearing Liverpool supporters. The leading role was played by Irvine Patnick, then MP for Sheffield Hallam, who contributed to the Sun newspaper’s disgusting lies about the behavior of Liverpool fans—published under the now infamous headline, “ The Truth.” Patnick died in 2012, still holding a knighthood.

Peter Wright, chief constable of South Yorkshire police at the time of Hillsborough, came under suspicion for diverting blame from members of the police but died in 2011. Stefan Popper, the coroner who oversaw the original and thoroughly discredited inquest into events at the stadium, died in 2016. Bernard Murray, the ground commander and Duckenfield’s immediate subordinate on the day, is also deceased.

The passing of time has also made it increasingly difficult to prosecute still-living suspects. Sir Norman Bettison, former chief constable of West Yorkshire Police, is a case in point. He was originally charged alongside the other five defendants, in his case, for lying about his part in South Yorkshire police’s response to the tragedy and about his views on the role fans played in it. But the prosecution was forced to drop proceedings against Bettison when a key witness died and the evidence of two other witnesses changed.

As it stands, just five people—aged between 68 and 80 and having since retired from their positions of responsibility—are standing or due to stand trial. Duckenfield himself is 74 years old, having been retired for almost three decades on a full index linked pension of £23,000 a year.

The lesson of these events is that the ruling class will not allow its representatives to be held to account for the crimes they inflict upon the working class and will fight tooth and nail to prevent justice from prevailing. This is especially significant considering their response to the Grenfell Tower fire, where a similar cover-up operation is underway. This is despite the ongoing struggle by local residents, who angrily denounced the Royal Borough of Kensington and Chelsea council in the immediate aftermath of the fire and insisted that the fight for justice for the victims of social murder at Grenfell not end up going down the same path as Hillsborough.

However, the fact is that the Grenfell public inquiry being held under Sir Martin Moore-Bick is designed to be a whitewash. From day one, it was specifically barred from discussing issues of a “social, economic and political nature” and “limited to the cause [of the fire], how it spread, and preventing a future blaze.” The first phase of the inquiry took nearly 18 months to complete. The next phase has been delayed until at least 2020. This was confirmed by Moore-Bick at the very end of the first phase of the inquiry in December, at the same time as the Metropolitan Police confirmed its investigation is expected to “take years” to complete.

The author recommends:

Criminal prosecutions finally brought 28 years after 96 Liverpool fans killed at Hillsborough stadium
[30 June 2017]

Second phase of Grenfell inquiry delayed for a year
[14 December 2018]

Saturn’s rings, younger than dinosaurs?


This March 2016 video says about itself:

Saturn’s Moons and Rings May Be Younger Than the Dinosaurs

Some of Saturn‘s icy moons may have been formed after many dinosaurs roamed the Earth. New computer modeling of the Saturnian system suggests the rings and moons may be no more than 100 million years old.

Saturn hosts 62 known moons. All of them are influenced not only by the gravity of the planet, but also by each other’s gravities. A new computer model suggests that the Saturnian moons Tethys, Dione and Rhea haven’t seen the kinds of changes in their orbital tilts that are typical for moons that have lived in the system and interacted with other moons over long periods of time. In other words, these appear to be very young moons.

“Moons are always changing their orbits. That’s inevitable,” Matija Cuk, principal investigator at the SETI Institute and one of the authors of the new research, said in a statement. “But that fact allows us to use computer simulations to tease out the history of Saturn’s inner moons. Doing so, we find that they were most likely born during the most recent 2 percent of the planet’s history.”

The age of Saturn’s rings has come under considerable debate since their discovery in the 1600s. In 2012, however, French astronomers suggested that some of the inner moons and the planet’s well-known rings may have recent origins. The researchers showed that tidal effects — which refer to “the gravitational interaction of the inner moons with fluids deep in Saturn’s interior,” according to the statement — should cause the moons to move to larger orbits in a very short time.

“Saturn has dozens of moons that are slowly increasing their orbital size due to tidal effects. In addition, pairs of moons may occasionally move into orbital resonances. This occurs when one moon’s orbital period becomes a simple fraction of another. For example, one moon could orbit twice as fast as another moon, or three times as fast. Once an orbital resonance takes place, the moons can affect each other’s gravity, even if they are very small. This will eventually elongate their orbits and tilt them from their original orbital plane. By looking at computer models that predict how extended a moon’s orbit should become over time, and comparing that with the actual position of the moon today, the researchers found that the orbits of Tethys, Dione and Rhea are “less dramatically altered than previously thought,” the statement said.

The moons don’t appear to have moved very far from where they were born. To get a more specific value for the ages of these moons, Cuk used ice geysers on Saturn’s moon Enceladus. The researchers assumed that the energy powering those geysers comes from tidal interactions with Saturn and that the level of geothermal activity on Enceladus has been constant, and from there, inferred the strength of the tidal forces from Saturn.

Using the computer simulations, the researchers concluded that Enceladus would have moved from its original orbital position to its current one in just 100 million years — meaning it likely formed during the Cretaceous period. The larger implication is that the inner moons of Saturn and its gorgeous rings are all relatively young. (The more distant moons Titan and Iapetus would not have been formed at the same time.)

“So the question arises — what caused the recent birth of the inner moons?” Cuk said in the statement. “Our best guess is that Saturn had a similar collection of moons before, but their orbits were disturbed by a special kind of orbital resonance involving Saturn’s motion around the sun. Eventually, the orbits of neighboring moons crossed, and these objects collided. From this rubble, the present set of moons and rings formed.” The research is being published in the Astrophysical Journal.

From Space.com:

Saturn’s Rings May Be Younger Than the Dinosaurs

By Charles Q. Choi, Space.com Contributor | January 17, 2019 02:01pm ET

Saturn has not always had rings — the planet’s haloes may date only to the age of dinosaurs, or after it, a new study finds.

The age of Saturn’s rings has long proven controversial. Some researchers had thought the iconic features formed along with the planet about 4.5 billion years ago from the icy rubble left in orbit around it after the formation of the solar system. Others suggested the rings are very young, perhaps originating after Saturn’s gravitational pull tore apart a comet or an icy moon.

One way to solve this mystery is to weigh Saturn’s rings. The rings were initially made of bright ice, but over time have become contaminated and darkened by debris from the outer reaches of the solar system. A few years back, NASA’s Saturn-orbiting Cassini mission determined that the rings are only about 1 percent impure. If scientists could weigh Saturn‘s rings, they could estimate the amount of time it would take for them to accumulate enough contaminants to get 1 percent impure and thus calculate their age, lead study author Luciano Iess, a planetary scientist at the Sapienza University of Rome, told Space.com. [Saturn’s Glorious Rings in Pictures]

Iess and his colleagues relied on more Cassini data. Before the spacecraft plunged to its death into Saturn’s atmosphere in September 2017, it coasted between the planet and its rings and let their gravitational pulls tug it around. The strength of a body’s gravity depends on its mass, and by analyzing how much Cassini was pulled one way or the other during the “grand finale” phase of its mission, the mission team could measure the gravity and mass of both Saturn and its rings.

During six of Cassini’s crossings between Saturn and its rings at altitudes about 1,615 miles to 2,425 miles (2,600 to 3,900 kilometers) above the planet’s clouds, scientists monitored the radio link between the spacecraft and Earth. Much as how an ambulance siren sounds higher pitched as the vehicle drives toward you and lower pitched as it moves away, the radio signals would lengthen in wavelength as their source moved away Earth and shorten as their source moved toward it — an effect called the Doppler shift.

“I’m astonished by the fact that we were able to measure the velocity of a distant spacecraft 1.3 billion kilometers [807 million miles] away from Earth with an accuracy that is a hundredth or a thousandth the speed of a snail — a few hundreds of millimeters per second,” Iess said.

Previous estimates based on data from the Voyager flybys of Saturn suggested the rings’ mass was about 28 million billion metric tons. The new data from Cassini now suggests the rings’ mass is only about 15.4 million billion metric tons. (The largest asteroid, Ceres, has a mass of about 939 million billion metric tons.)

All in all, the researchers suggest the rings formed between 10 million to 100 million years ago. In comparison, the age of dinosaurs ended about 66 million years ago.

Cassini’s grand finale also revealed key details about the internal structure of Saturn. For example, it found that jet streams seen around Saturn’s equator — the strongest measured in the solar system, with winds of up to 930 mph (1,500 km/h) — extend to a depth of at least 5,600 miles (9,000 km), rotating a colossal amount of mass around the planet about 4 percent faster than the layer below it.

“The discovery of deeply rotating layers is a surprising revelation about the internal structure of the planet,” Cassini project scientist Linda Spilker at NASA’s Jet Propulsion Laboratory in Pasadena, California, who did not participate in the study, said in a statement. “The question is, What causes the more rapidly rotating part of the atmosphere to go so deep, and what does that tell us about Saturn’s interior?”

The new findings also suggest that Saturn’s rocky core is about 15 to 18 times the mass of Earth, similar to prior estimates.

The scientists detailed their findings online Jan. 17 in the journal Science.

How an ancient amphibian moved, video


This 16 January 2019 video says about itself:

Watch researchers re-create how an early tetropod moved | Science News

To examine possible gaits for Orobates pabsti, a creature that lived 290 million years ago, researchers used a robot (dubbed the OroBOT) as well as digital simulations of different walking styles. Here, scientists watch as OroBOT struts its stuff, moving forward without much side-to-side undulation and with relatively erect legs that hold its belly off the ground. Using a digital simulation (top) and the OroBOT (bottom), the researchers [reconstruct] the footprint pattern left by O. pabsti using an erect, non-undulating gait.

By Carolyn Gramling, 1:27pm, January 16, 2019:

A four-legged robot hints at how ancient tetrapods walked

Orobates pabsti may have had a more developed gait that previously thought

Orobates pabsti lived between 280 million and 290 million years ago, but it was pretty advanced at doing the locomotion.

Using computer simulations, re-created skeletons, fossil trackways and a walking robot dubbed the OroBOT, scientists found that this ancient four-footed creature had a surprisingly efficient gait. The result suggests that developing a more advanced way of walking may not have been as closely linked to the later diversification of tetrapods as once thought, the researchers report January 17 in Nature.

Scientists care about how O. pabsti might have moved because the animal was one of the earliest amniotes,

There is disagreement among scientists whether Diadectids, the family to which Orobates belonged, were ‘already’ amniotes or ‘still’ amphibians.

a group that arose around 350 million years ago and includes both reptiles and mammals. Unlike amphibians, which have aquatic young, amniotes can live entirely on land. Protective membranes surrounding embryos allow amniotes to bypass a tadpole-type life stage in water: Reptile (including bird) eggs can be laid on land in nests; mammal embryos stay within the mother.

The amniotic membrane “is regarded as a key evolutionary innovation, to be able to colonize different habitats,” says John Nyakatura, a paleontologist at the Humboldt University of Berlin who led the new study.

Understanding how early amniotes walked on land could help scientists better understand the origins of amniotes themselves, and how they eventually diversified across the continents, Nyakatura says. “Orobates, our focus fossil in this story, is a very close cousin to the last common ancestor of mammals and reptiles,” he says.

Researchers first described O. pabsti in 2004, following the discovery of beautifully preserved fossils of the creature at a site in central Germany known as the Bromacher locality. “The preservation is phenomenal,” says Stuart Sumida, a vertebrate paleontologist at California State University, San Bernardino who was not involved in the new study. “These are things preserved from the tip of the nose to the tip of the tails,” Sumida says. “They are so well preserved that we can generate hypotheses about how they moved.”

Then, a few years later, researchers linked the creatures to a series of footprints, called a trackway, found at the same locality, offering more clues to how the animal might have walked.

STEP BY STEP In 2007, scientists determined that these fossil trackways were made by Orobates pabsti. Both a fossil skeleton and these trackways were essential to a new study’s analysis of how O. pabsti might have walked. Photo Sebastian Voigt/Urweltmuseum Geoskop Thallichtenberg

In 2007, scientists determined that these fossil trackways were made by Orobates pabsti. Both a fossil skeleton and these trackways were essential to a new study’s analysis of how O. pabsti might have walked.

But there’s more to visualizing walking than knowing where an animal put its feet. Various approaches are used to study the locomotion of extinct animals, including examining their anatomy from fossils, studying trackways (SN: 1/30/10, p. 9) or even building robots, says study coauthor Kamilo Melo, a bioroboticist at École Polytechnique Fédérale de Lausanne in Switzerland. But what’s different about the new study, Melo says, is that the scientists have combined several of these tactics to get the best possible approximation of an ancient creature’s gait.

The researchers first re-created the skeleton of the creature and used it to constrain the possible ranges of motion of arms and legs, called a kinematic simulation. “You create a marionette, and see what amount of angle each joint can move,” Melo says. And the scientists created a dynamic simulation, which included factors such as gravity, friction and balance, to really examine how the animal might have walked.

The team also looked to modern four-footed species, including salamanders, skinks, caimans and iguanas, to examine possible ranges of motion for tetrapods. Skinks and salamanders, for example, hold their bodies lower with their limbs more sprawled out to the side while caimans tend have more erect limbs.

Finally, the scientists created a tetrapod robot, dubbed the OroBOT, to act out potential gaits and match the prints they’d create to the fossil tracks. The researchers ultimately considered 512 different possible types of movement, scoring them on scales such as energy consumption, balance and precision — how well the gait reproduces the fossil tracks without slipping or sliding. (The researchers have also put their digital simulation online; try out different gaits here.)

The data suggest that O. pabsti had a relatively advanced style of walking, one that researchers previously thought would have belonged to later tetrapods. It held its belly off the ground, and had a stable, efficient gait without a lot of side-to-side, salamander-like undulations. That style of walking probably helped the animal conserve energy.

Sumida praises the study’s multipronged design, which allowed the scientists to test their findings in multiple ways, from fossil to digital simulations to robot. Furthermore, he notes, the team’s biomechanical analysis has confirmed something that previously was strongly suspected only by the fossil’s finders: that O. pabsti was indeed a fully terrestrial animal that probably had a relatively modern gait.

Sumida and others have demonstrated that amniotes from the same locality were using a range of different walking styles. Some had erect limbs like O. pabsti, some sprawled, and at least one animal walked on two legs. “What these studies are showing is that when amniotes first showed up, they were doing lots of things more quickly than we ever realized,” he says.

The findings are just a start, Nyakatura says. The researchers hope their multipronged approach will be a jumping-off point, not only for scientists to better understand O. pabsti, but also to examine other ancient locomotive puzzles, such as the evolution of active flight, bipedal locomotion in human ancestors and the transition from terrestrial to aquatic in marine mammals. “We have a whole bag of interesting things to study,” he says.